Conveying means for envelope dryers and the like



Jan. 12, 1960 v. E. HEYWOOD CONVEYING MEANS FOR ENVELOPE DRYERS AND THE LIKE H Filed D90. 26, 1957 4 Sheets-Sheet 1 mm: BY

w FYI/W Jan. 12, 1960 v. E. HEYWOOD 2,920,748

CONVEYING MEANS FOR ENVELOPE DRYERS AND THE LIKE Filed Dec, 26, 1957 4 Sheets-Sheet 2 "xii N N I l 2 i i s. ..l '5 [g m I 0 \0 MN T n E m i v. ---1. l Ix i \R s, Q N n O N U n l Q #3 INVENTOR. Vincent EHeywood Jan. 12, 1960 v.- E. HEYWOOD 2,920,748

I CONVEYING MEANS FOR ENVELOPE DRYERS AND THE LIKE Filed Dec. 26, 1957 4 Sheets-Sheet 3 Illlllh$ IN VEN TOR.

Vz'ncenl EHeywood Jan. 12, 1960 v. E. HEYWOOD CONVEYING MEANS FOR ENVELOPE DRYERS AND THE LIKE Filed Dec. 26, 1957 4 Sheets-Sheet 4 INVENTOR T zncerzl" 51%,vw00a 1/ BY M ATTORNEY United States Patent CONVEYING MEANS FOR ENVELOPE DRYERS AND THE LIKE Vincent E. Heywood, Worcester, Mass., assignor to United States Envelope Company, Springfield, Mass., a corporation of Maine Application December 26, 1957, Serial No. 705,237

Claims. (Cl. 198-180) poses, have been progressively collected into a slow moving closely overlapped or shingled assembly.

Such a closely shingled assembly, by reason of exposing only the marginal areas of the successive articles trailing seal flaps, allows the seal flap gluing to be applied continuously or en masse, by the well-known coating or spreading process. It is highly advantageous, for economy of dryer length and space, to keep the articles, during their subsequent passage through a drying tunnel or the like, in substantially this same closely overlapped or shingled relation.

It has heretofore been the practice, for advancing such a shingled assembly of fiat freshly-glued articles through a drying tunnel, to contact the assembly, top and bottom, by laterally spaced pairs of flexible traveling belts, substantially as disclosed by Winkler and Dunnebier Patent No. 2,132,227 of October 4, 1938.

If the freshly-glued articles, as in the aforesaid Winkler and Dunnebier patent, are flat unfolded envelope blanks, their shingled or overlapped relationship can usually be kept intact and undisturbed, when this conventional opposed belt arrangement is employed. This is because the blanks, being of single thickness and relatively flaccid, maintain with each other such large areas of contact, with virtual exclusion of air from these interface areas, as to effectively resist the tendency of any individual blank or blanks to shift, creep, or otherwise get out of parallelism with the other freshly-glued blanks of the advancing shingled blank assembly.

But these optimum conditions do not exist or prevail, when the shingled freshly-glued articles, instead of being flat unfolded blanks, are partly-folded blanks, as in Kennedy Patent No. 2,811,905 of November 5, 1957, or are virtually completed envelopes, as in Heywood. Patent No. 2,851,934 of September 16, 1958. When the conventional opposed flexible belt arrangement is employed with shingled freshly-glued articles of this nature, many of them will creep out of parallelism with their fellows, entailing widespread and frequent fouling and wastage of the blanks and/or envelopes, as well as numerous interruptions of the manufacturing process. These difiiculties stern, not only from the much greater stiffness imparted by these articles folds, but also from the fact that their areas contacted by the opposed flexible belts consist of different numbers of thicknesses of the blank and/or envelope material.

The primary object of this invention is to overcom these difficulties, by providing for envelopes, envelope blanks and similar flat articles delivered in stepped or shingled relation, a conveying means that preserves said relation intact,v and effectively resists all tendencies of any individual article or articles to shift, creep or otherwise get out of parallelism with the other articles of the advancing shingled assembly Other and further objects and advantages of the invention will become apparentfrom the following detailed description thereof, taken in'connection with the accompanying illustrative drawings, in which Figs. 1 and la taken together provide a side view, partly in section, of an elongated drying tunnel for envelopes and the like, equipped with the conveying means of this invention. I e

Fig. 2 is a larger scale. sectional. view, substantially on the section line 2-2 of Fig. 1a. I

Fig. 3 is a large scale plan view, with some parts omitted, of apparatus at the right-hand end of Fig. 1.

Fig. 4 is a fragmentary plan view, on a still larger scale than Fig. ,3, of a short piece of one of the double 'roller conveyor chains usedfwith this invention.

Fig. 5 is a fragmentary sectional view on the line 55 of Fig. 2, and t Figs. 6 and 7 arefragrnentary sectional views, similar to Fig. 2, showing a modified form of the invention.

Referring first to Fig. 3, and to the right-hand end of Fig. 1, the reference character E designates a continuous succession of envelopes, as progressively collected for seal flap gluing in a closely overlapped or shingled assembly. Envelope assembly E moves at relatively slow speed, in the direction of arrow A, for the continuous or en masse gluing, by the well-known coating or spreading process, of the envelopes trailing seal flaps. Conventional equipment .for such gluing, as shown in Fig. 1, includes a glue supply tub 1. and a glue transfer roll 2, the latter supplying glue to an upper roll 3 which cooperates with a lower roll 4 to continue the slow speed advance of envelope assembly E... Roll 3 spreads glue in a band .5 of uniform width onto the exposed and adjacent marginal seal flap areas, the width of said band 5 being appreciably less than the seal flap length, such as to leave along both lateral edges of envelope assembly E, the narrow unglued areas. that are designated in Fig. 3 by the reference characters 5a, 5a.

These unglued marginal'areas 5a, 542 permit the advance of shingled assembly E to. be continued, in conventional fashion,by a lower roll 6, and acooperating pair of narrow upper rolls or discs 7, 7 contactingthe unglued areas 50, 5a, for the continuous slow speeddeliveryfof the shingled freshly-glued envelopes to the apparatus. of this invention. Said apparatus includes a drying tunnel, or like enclosure, designated generally in Figs. 1, 1a and 2 by the numeral 8. This invention is concerned with the progressive uniform advancement through the full length of said drying tunnel, of the continuous envelope assembly E, in such manher as to maintain intact, without displacement of any individual envelopes, the illustrated shingled or overlapped relationship. This permits the envelopes freshly-glued seal flaps to be gradually dried, as by heated air introduced to the interior of tunnel ,8, through anysuitable inlet duct, as shown at 45, Figs. 1 and 1a.

As shown in Fig. 1, the shingled envelope assembly E passes into the tunnel through a narrow horizontal entrance slot 22 provided bythe tunnels end wall 23. The tunnel s opposite end wall provides a corresponding delivery slot 22 (Fig. 1a) through which the assembly E, with gluedse'al flaps fully dried, has continuous exit.

For the assemblys horizontal support, before, during and after such drying, the invention provides (see Fig. 2) a central elongated skid 26, and apair of laterally flanking elongated skids 9, 9, all with their upper sur faces in the same horizontal plane as the bite of the rolls 6, 7. These skidsnot only run for the drying tunnels full length, but they project outwardly for a Patented Jan. 12, 1960 considerable distance through said tunnels entrance and exit openings 22 and 22' respectively, as shown in Figs. 1 and 1a. The central skid 26 is suitably supported from the tunnels floor by a series ofspaced-apart brackets "28, one of which is shown in Fig 2. All three skids'preferably have their upper material-supporting surfaces covered or coated with a layer of anti-friction material such as Teflon, as indicated at 9a, 9a and 26a, in Fig. 2.

For the support of lateral skids 9, 9 (and also for their sidewise adjustment to accommodate envelopes of different lengths) thedrying tunnel is equipped with a plurality of transverse spaced apart shafts 30,30, here shown as four in number. Each shaft 30, as shown in Fig. 2, is suitably journalled in thetunnels side walls, and at its opposite ends carries suitable washers 37, nuts 36 and lock nuts 35, by ,which to hold it from any endwise or axial displacement. Within the tunnel interior; each shaft 30 has oppositely threaded portions-3 1 and 327re speotively, which are separated. by'a central unthreaded portion 33. Topside .ofeachsuchthreaded portion131 or 32 -is mounted a correspondingly; threaded half-nut, as shown respectively at 34 and 34' in Fig. 2. Each somounted half-nut, as shown in Fig. 5., presents a'flathor- I izontal upper surface 27, by which to provide one of a series of supporting surfaces, all at the same level, for each of the elongated lateral skids 9, 9. The latter, as shown in Fig. 2, are attached to each underlying halfnut by a suitable pin 24.

Along one side of drying tunnel 8, the projectingend of each of the shafts 30, 30 carries a sprocket-wheel 38. These several alined sprocket wheels are rotatable in unison in either direction by a common endless chain, not shown. By this arrangement, the two elongated lateral skids 9, 9, along whose outside edges move the unglued marginal areas 5a, 5a of the shingled envelope assembly E, can be made to move toward each other, or away from each other, as desired, in order to conform the width of assemblys elongated supportingsurface to the'length dimension of the envelopes that are being advanced in shingled relation, through the drying tunnel 8.

For effectively procuring such advance, along the full length of the elongated supporting skids 9, 9 and 26, this invention employs, for cooperating with the materialsupporting outside edge areas of the two lateral skids 9, 9, a pair of suitably equipped parallel. double-width endless metal roller chains, as illustrated in Figs. 3 and 4. This cooperation is provided by the two chains lower courses which extend over said edge areas for the fun- :nelfs full length and which are of sufficient slackness for substantial portions of their weight to be sustained, as hereinafter described, by such material-supporting edge areas of the skids 9, 9. The two chains are driven in unison, each through the travel path indicated by the arrowed dot-and-dash lines 10, 10 of Figs. 1 and la. This path requires the lower course of each chain to run alongside to and parallel with the envelope supporting surface of its associated skid 9 for substantially the latters full lengthwith said lower course entering the tunnel 8 through slot 22 and leaving said tunnel by way of exit slot 22'.

Each chain is given this path 10, 10 by being trained, outside the tunnels entrance end, about suitable driving and idler sprockets 13 and 16 respectively, and by being similarly trained, outside the tunnels exit end, about suitable driving and idler sprockets 14 and 15 respectively. Sprockets 13 and 16 are carried by an upright or bracket 39-that is permanently attached to the portion of skid 9that extends outwardlyfrom entrance slot 22. Similarly, the sprockets 14 and 15 are carried by an upright or bracket 40 that is permanently attached to other exremeend of skid 9, beyond the 'tunnels exit slot 22. Thusxit is that whenever the'two skids 9, 9 are adjusted toward or away from each other, as above described, to change the width of the shingled assemblys material-supporting surface, each chain is bodily shifted sidewise in I 4 unison with its associated skid 9, so as to maintain in every case the positional relationship of each chains skid-supported lower course to its associated skids envelope supporting surface.

Both chains are preferably of the conventional doubleroller construction shown'ibythe lower half of Fig. 4, this giving each chain an inner section 17, and an outer section 18. Each section provides the usual links 19, pins 20 and rollers 21, the pins 20 being common to both sections 17 and 18, so that the double width chain, as far as articulation is concerned, functions in the same fashion as a roller chain having a single row of rollers.

The always-maintained positional relation of each chains lower course with the envelope supporting surface of its associated skid 9 is shown by Fig. 2. As therein shown, each skid 9, outwardly of its envelope supporting surface, has an extension 29 of reduced thickness, that terminates ina-narrow upright guiderail 25,

running the full length of said skid. Each rail 25, slightly narrower than the chain rollers 21, 21, is surmounted and engaged, as shown, by the outer section 18 of the associated chains lower course, thus to provide full length guidance for, and to partially support the weight of, said chains lower course. The balance of' the weight of each chains. lower course is received, as shown by Fig. 2, upon the unglued marginal areas 5a, 5a of envelope assembly E, that lie along the outer edge of each skids support surface, said chain weight being transmitted to these unglued assembly areas by a multiplicity of closely adjacent resilient pads or cushions '12, 12 (see Fig. 4), each secured to and depending from a suitable lateral bracket 11 extending inwardly from the inner section 17 of the chain, between the latters articulations.

The effect of the thus-transmitted weight of each traveling chains lower course is to strongly compress the unglued marginal edges of shingled envelope assembly E between the pads 12 and the underlying outer edge support areas of the associated skid 9. In consequence of this compression, distributed evenly throughout the full length of each skid, there is no tendency or opportunity for any individual envelope or envelopes, during the chains dragging of assembly E along the skids, to creep, slip, or otherwise move out of parallelism with its fellows. Such movement of assembly E, always in unison with the chains lower courses, is certain to transpire. This isbecause the smooth .flat'unbroken skid surfaces offer much' less frictional resistance to said assemblys under surface than the'topside frictional resistance that exists between said assembly E and the spaced gravityurged pads or cushions 12, 12. Beyond said tunnel each successive foremost envelope of; assembly E is seized by suitable high speed rolls 43, 44, Fig. la, and so accelerated as to separate it fromsaid assembly, preparatory to any desired further operations thereon.

Figs. 6 and 7 illustrate a somewhat different construction for the laterally adjustable skids, from that shown by the laterally adjustable skids 9, 9 of Fig. 2. With the lateral ,skid 41 shown by Figs. 6 and 7, the elongated support for the unglued marginal areas 5a, 5a, of envelope assembly E is provided byan inwardly directed shelf 42. Outwardly of "said shelf-,-each skid 41 has a pair of narrow spaced-apart upright rails 46, 46 which underlie the respective inner and outersections 17 and 18 of the above-described double roller chain. Said chains inner section 17 between its articulations, provides suitable laterally, extending brackets 11a, 11a, each carrying, in overhanging relationto the skids shelf 42, a suitable pad or cushion 12a for transmitting a substantial portion of. the traveling chains weight to the assembly s unglued marginal, areas 5a, 5a.

In this case, however, the.do uble roller chains outside section 18 is also equipped with a set of laterally extending brackets.47., 47.' [E'achofthese brackets 47 provides downwardlyextendirig pin 48 on which is journaled a roller 49. These rollers 49, 49 of the traveling chains lower course enter and move with ample clearance along and through an open relatively wide groove or recess 50 which runs the full length of skid 41, outwardly of the latters rails 46, 46. Said elongated groove or recess 50 thus serves for the lateral guidance of the roller chains lower course, for the full length of skid 41.

In the absence of envelope assembly E, as shown in Fig. 6, the support of said roller chains lower course is by the two rails 46, 46 of elongated skid 41. These rails are of suflicient height, such that, under these conditions, the lower surfaces of pads or cushions 12a, 12a will just clear the supporting surface provided by the skids shelf v 42. But when the envelope assembly E is present on the skids, as shown in Fig. 7, the chains lower course tilts slightly into the position shown by Fig. 6. In that situation, wherein the two chains lower courses are dragging envelope assembly E along the skids, the weight of both lower courses is taken off the rails 46, 46, and put, in large measure, upon the unglued marginal areas 5a, 5a of said envelope assembly, substantially as in the first described form of the invention. Under these conditions, rollers 49, 49 continue to provide lateral guidance for each chains lower course, by virtue of their rolling contact with the outer wall 51 of the skids groove or recess 50, said outer wall, to accommodate this slight tilting of each chains lower course, being preferably given a slight outward slope from the bottom of recess 50, as best shown in Fig. 7.

I claim:

1. Apparatus for conveying envelopes in stepped or shingled assembly through a drying tunnel or the like and for maintaining intact their stepped or shingled relationship, comprising an elongated horizontal smooth-surfaced support onto which the shingled envelope assembly is progressively delivered, a pair of spaced parallel endless metal chains, having relatively slack lower courses adjacent to and coextensive with opposite marginal areas of said envelope assembly that are underlain by said support, means for driving said chains in unison, and a plurality of devices projecting inwardly from each chain, which are carried by its lower course into topside frictional contact with said assemblys proximate marginal area, to compress the latter by portions of said lower courses weight, and to advance said assembly by frictional forces in excess of the frictional resistance to assembly movement imposed by said smooth-surfaced support.

2. Conveying apparatus as claimed in claim 1, in which the support for said envelope assembly is a pair of spaced elongated skids, in underlying relation to the respective marginal areas of said assembly.

3. Conveying apparatus as claimed in claim 2, in which the skids are laterally adjustable, to conform their spacing to the length dimensions of the assemblys envelopes.

4. Conveying apparatus as claimed in claim 3, in which the chains are carried by and are laterally adjustable with the skids.

5. Conveying apparatus as claimed in claim 1, in which the devices projecting inwardly from each chain are a multiplicity of resilient pads or cushions.

6. Conveying apparatus as claimed in claim 1, in which each chain is a double roller chain, whose inner section carries the devices for compressing and frictionally engaging the envelope assemblys proximate marginal area.

7. Conveying apparatus as claimed in claim 6, in which each double roller chains outer section, along the chains lower course, is guided and supported by an underlying elongated rail.

8. Conveying apparatus as claimed in claim 7, in which each chains lower course has pivotal movement on said rail in accommodating itself to changes in the thickness of said shingled envelope assembly.

9. Conveying apparatus as claimed in claim 2, in which additional support for said shingled envelope assembly is provided by a central elongated skid midway of said spaced skids.

10. Conveying apparatus as claimed in claim 9, in which the skids material-supporting upper surfaces are coated or covered with an anti-friction material.

References Cited in the file of this patent UNITED STATES PATENTS 

